GMS81C50 Datasheet, PDF (97/99 Pages) Hynix Semiconductor – 8-BIT SINGLE CHIP MICROCONTROLLERS

Appendix B. Programmer’s guide
KEY MATRIX
= KEY
Figure B-1. Circuit Diagram
Note: Normally use the above 100uF capacitor for prevent power drop during pulse is transmitted. If you use the SRAM back-
up, use at least 220uF.
We recommend to use ALKALINE battery.
Note: Figure B-1, Circuit Description:
device : GMS81C5016
package : 40PIN PDIP
port R0x : All input port with pull-up resistor
port R1x : All output port with N-MOS Open drain
port R11 : LED Drive port
B-2